Fat Tires & Ignition Timing

Currently I have been spending the evenings in the garage trying to stuff the widest tire possible into the rear of my RD. This puzzle is all about finding just the right combo of rubber, chain length, sprocket size, and not have clearance problems between the tire and swingarm. Last night I dumped my box of chains and sprockets on the garage floor and started working out the best "combo". After trying several combinations, I have settled on 98 links, 17T front sprocket, and a 38T rear sprocket. This combo gives me about a 6mm gap between the new Pirreli "Sport Demon" 120/80-18 and the swingarm, but the gearing is not my favorite option. I would rather have a 40T sprocket on the rear! Now the ignition timing..... The 3mm BTDC on my MZ ignition is a bit extreme and I'm more than a little worried about frying a piston. This weekend I am going to experiment and test-ride settings between 1.7mm and 2.0mm BTDC. I just can't reliably get (or afford) the 115 octane leaded race fuel that I need for the 3mm advance. At about $12 / gallon, the race fuel really limits my riding options. I am planning an "epic ride" this summer and I want to complete the journey without melting a piston of seizing the motor! If I get the taxes done this week, I should be testing various ignition settings all weekend. Stay tuned for the results.

Rockers vs Mods 2011

Time flies and now it's almost time for the 5th annual "Rockers vs Mods" event in Dallas! April 1st - 3rd Dallas will be transformed into a cafe racer's gathering, with bands, rides, bar runs, bike shows and assorted shenanigans. I hope to attend, but it will probably be for just Saturday, April 2nd. The RD still looks pretty ratty, dented tank and I still need to get around to painting the bike. Sure hope to make the event!

UPDATE: 3/31/2011 Looks like I'll be in the garage working on the RD while everyone is partying at Rockers vs Mods! A rear wheel bearing failure and dificulty in procuring several parts have made the timeline undoable! Maybe next year....

Spring Is Here, Time to Ride!

Spring has officially sprung and I have sprung into action getting the RD Racer back on the road. This weekend I completed a tear-down of the carbs, charged the little micro-battery, and spent some time puzzling over the rear wheel alignment. Right now the rear wheel is my "big issue".

My quest for more grip led me to install a wider rear tire and now swingarm clearances are an issue. Hard cornering, my 180 lbs, and vintage 1970's chrome-moly all lead to some pretty substantial swingarm flex. After a hard ride with lots of aggressive cornering, I can see where the tire has rubbed the swingarm! I am moving the rear wheel back about 10mm to increase clearances.

Should be test riding this weekend!

Barcelona & MotoGP

Been away for awhile, but still having fun and working on the RD. Two weeks in Barcelona, with lots of time at the beach and the Circuit de Catalunya. The races were unreal and Barcelona is a beautiful city. Lorenzo won the main event while we sat with the Lorenzo Espania Fan Club. Very fun crowd.

I could so easily live in Spain! The Spanish are motorcycle CRAZED and the whole vibe is quite relaxed. Beaches, bikes and hot Spanish women... What's not to like?

I saw a wide assortment of 2-stroke sportbikes in Barcelona. Lots of CBR250RR's, Yamaha 250's and even a tricked out vintage Bultaco cafe racer.

I'm Healed!

Just over six months have passed since my collision with the killer dog and I am still hurting. Mainly it is my shoulder that hurts, but at least I am riding.


I have been riding my Gixxer, pushing harder and harder going on longer and faster rides. Now I'm ready to break out the "Punisher", my RD400. The RD is partially disassembled in the garage and this weekend I'll put all the lovely bits back together again.

RD Racer Version 2.0

Last night I completed the teardown of the next RD400 "donor". The "donor" RD is a 1978 US model that was about 70% complete and barely running on one cylinder. I competed the teardown in about 2 hours and now the fun begins.

My goal for this RD is to go a bit more radical than I did with the first RD. I will be using a RZ350 front end (forks, triples, rotors & brakes), a modified FZ600 swingarm in the rear, and RZ350 wheels front and rear. I will encase the bike in a 1986 TZ250 full fairing and bodywork. The engine will not be as heavily modified as the previous RD project and I'll keep the stock Mikuni 28's with a 2 into 1 intake. For the ignition I'll be using a generation 2 Nuetronics unit and the expansion chambers will be old Stage-II units.

After I degrease the frame and stock swingarm, it's off to the sandblaster and a couple of hours with the grinder. While the frame is being sandblasted I'll start the teardown on the engine.

This project will require more fabrication than the previous RD, but I am in no hurry to complete the project. If everything goes perfect (that's not going to happen), I could be done by summer.

All the King's Horses & All the King's Men.....

The RD lives again, all crash damage repaired and she is better than ever.... Work done included....

New fork with pneumatic adjustment
New Woodcraft clip-on's
New grips
New stator cover - Polished aluminum finish
New left-side shifter rear-set
New license plate hanger
New fuel tank & petcock (No dents, but it sure is BLUE!)
New left-side chain adjuster
New front fender mounts
New clutch lever

I added a nice CNC machined front rotor and moved the previous drilled front rotor to the rear brake. A nice touch and the CNC'ed rotor offered a minor increase in thickness.

After everything was bolted back together and buttoned up, it's time for a test ride! The test ride went OK (I didn't hit any stray dogs) , but I did uncover some issues....... First I noticed that the engine is running rough and then I noticed the sweet smell of pre-mix gas. A quick inspection shows that the petcock gasket is leaking and the right - side carb is dumping gas from the overflow. The new clear gas lines expose the grit and trash that washed out of my new "clean" tank.

Next steps...... pull the tank, flush it AGAIN and seal the petcock better. Then it is time to rebuild the Keihin PWK's and take another look at the ignition timing. My current timing settings require that I run 110 octane VP race fuel at about $7 / gallon.... OUCH!

I have a modified FZ600 swingarm coming in the mail (thank you eBay and Jibco520). Can't wait to play with the swingarm configurations. Stay tuned for some swingarm experimentation!